Simple question with probably lengthy answers. I just purchased 2 Turnigy 6S 5000mah 30C to see if they will last longer than my 20C Turnigys. One of my Turnigys are going bad at 50 cycles already. I am hoping that the 30C's will last longer. I haven't gotten them yet, but will test when I do.

I had a buddy tell me that when the battery gets old, the C rating actually drops off to a decent amount. He stated my 20C are probably running at around 18C or less now. I didn't know that the C rating actually lowers as the battery ages. What do you guys think?

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When you don't feel like soaring through the wind with a plane,, BEAT IT INTO SUBMISSION WITH A HELI!!!

Correct ....the C rating is affected because the electrolyte is oxidizing as it ages, hence the increase in internal resistance.

A few years ago companies were rating the life cycle expectancy based on discharging at 50% of the continuous C rating. A 20C continous lipo should be discharged at 10C for maximum life.

To answer your question....all things being equal a 30C lipo will last longer than a 20C lipo. The main issue with higher C lipos is the weight penalty that you incur which may throw off your CG. You may also have mounting issues due to the increase in physical size over the same mah lower C pack.

With the new substrates in the packs now the prices are dropping almost monthly. You can pick up higher C rated batteries now that charge faster, weigh less etc starting at around 50 bucks. I am on a limited budget so buying 4 packs and flying pretty much steady is better then buy 10 zippies and 5 chargers to do the same thing. In the end the prices pretty much match up. One way you just need 1 charger and 3-4 packs to fly all day cycling through them. The other your charging for an hour with multiple chargers and as some said on this site up to 10 packs.